For those of you who loved the original voice actor behind Splinter Cell Agent Sam Fisher (or if you enjoyed the original Total Recall), you might be sad to hear that Ironside is not involved in the Splinter Cell franchise. The loss of Ironside has been explained however, by the fact that new motion capture technology was not possible for 62-year-old actor.
The explanation can be found here at IGN.com, as it explains that the new “killing in motion” motion capture technology has to be done by the same actor. The voice and physical mannerisms are now a package deal since this new technology has them working together. This meant that while technology will give video games better and more realistic movement; a younger actor was needed to portray Sam Fisher.